Use of mineral spa water and seawater has been and continues to be a common treatment modality for inflammatory skin conditions such as psoriasis, atopic dermatitis, and irritant contact dermatitis. Spa or mineral water and seawater are noted for their relatively high concentrations of minerals such as strontium and selenium and for their high osmolality relative to physiological saline. Despite widespread use, few studies have explored what accounts for the therapeutic effect of seawater or its mechanism of action.
Recent in vivo and in vitro studies lend credence to the common practice of applying seawater to infl amed skin. In acute eruptions of atopic dermatitis, seawater exhibited antipruritic effects. There was a signifi cant reduction of visual analogue scores for itching, which was evaluated. The reduction of visual score of itching went from 15.05 to 2.35 (P<0.01) after 4 weeks of therapy. In the setting of irritant contact dermatitis, seawater compresses significantly decreased transepidermal water loss (TEWL) and increased skin capacitance compared with the deionized water control when the compresses were applied for 20 minutes at a time for several times over the course of 2 weeks. TEWL indicates water barrier disruption, while capacitance signifi es stratum corneum (SC) water content. Thus, the results provide evidence for seawater’s ability to inhibit skin barrier disruption and inhibit SC dryness in irritant contact dermatitis.